diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index b9be442f..56e7ca59 100644
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -721,7 +721,7 @@ LWS_VISIBLE void lwsl_emit_stderr(int level, const char *line)
 	for (n = 0; n < LLL_COUNT; n++)
 		if (level == (1 << n)) {
 			now = time_in_microseconds() / 100;
-			sprintf(buf, "[%lu:%04d] %s: ", (unsigned long) now / 10000,
+			sprintf(buf, "[%llu:%04d] %s: ", (unsigned long long) now / 10000,
 				(int)(now % 10000), log_level_names[n]);
 			break;
 		}
diff --git a/lib/lws-plat-unix.c b/lib/lws-plat-unix.c
index 9af4bdfd..1b831878 100644
--- a/lib/lws-plat-unix.c
+++ b/lib/lws-plat-unix.c
@@ -8,7 +8,7 @@ unsigned long long time_in_microseconds(void)
 {
 	struct timeval tv;
 	gettimeofday(&tv, NULL);
-	return (tv.tv_sec * 1000000) + tv.tv_usec;
+	return ((unsigned long long)tv.tv_sec * 1000000LL) + tv.tv_usec;
 }
 
 LWS_VISIBLE int libwebsockets_get_random(struct libwebsocket_context *context,